<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>堆快照查找分离DOM</title>
    </head>
    <body>
        <button id="btn">Add</button>
        <script>
            let tem
            function fn(){
                let ul = document.createElement('ul')
                for(let i = 0; i < 10; i++){
                    let li = document.createElement('li')
                    ul.appendChild(li)
                }
               
                tem = ul
                tem = null
            }
            document.getElementById('btn').addEventListener('click', fn)
        </script>
    </body>
</html>